Defrost Timers! So are we talking about Spring Break? The Sarah Connor Control Chronicles

It is that time of year when a desire to defrost from winter sends our minds dreaming of a warm beach Spring Break, right?  While it may not be quite as exciting as a college visit to Senor Frogs, this is a great time to talk about Defrost Timers.  So what exactly is a defrost timer, and why should the control you chose be rated to UL873?


A defrost timer is a cycling device that is found in refrigerators and freezers, keeping the evaporator coils from freezing up.  Excessive frost on the coils limits the airflow, causing reduced efficiency, and eventually failed cooling function.  So a defrost timer has two modes.  It spends most of its time in the cooling mode when it activates the compressor, but then it switches to heating mode activating the defrost heater to remove the frost from the coils.  But the timer is a motor, and just like any device with constantly moving parts, it can wear out.  Sometimes it gets stuck in one mode or the other, so you can manually advance it to check for function, and rule out other possible problems.


In a commercial refrigeration application, when you have determined that the defrost timer needs replacing, I, the very controlling Sarah Connor, recommend that you consider installing a Paragon Universal Defrost Timer.  Don’t even think about using an electric timer that is only UL917 rated.  This standard isn’t at all suited to commercial refrigeration, with a life cycle of just 6,000.  It is rated to work at room temperature, and it has no load requirement.  Instead, install a Paragon Universal Defrost Timer that is UL873 rated.  With a life cycle of 30,000, it is rated to operate 30-130 degrees F, with a load maximum of 30A.  Obviously, the Universal Paragon Defrost Timer will last five times as long when it is called upon to defrost four times per day.


And while it may not offer the satisfaction of a “spring break beach defrost,” when it comes to commercial refrigeration applications, you will be glad that you chose the Paragon Universal Defrost Timer!

For more information on defrost timers contact one of the control pros at if you are looking for Dwyer products in Georgia or Florida. If you are in another part of the country you can contact one of Sarah Connor’s friends at Controls Group North America.




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